19. This device will not use lithium 6, but calculations and laboratory experiments indieate it will be required in cuantity for usc in other designs of thermonucicar devices, plant for separating A- pilot this isotope is in operation at Oak Ridgc, and 2 plant capable of producing the matertal in quantity is to be constructed at Oak Ridge for operation by about January, 1953. 20. 4 possible range of yield for this device has been estimated at between 1 and 15 megatons TNT equivalent, to 15,000 kilotons TNT equivalent; or 1,000 this would be 50 to 750 times ete portes Ol. A specin] group has been established at the Los Alamos Selentific Laboratory to coordinate and direct the design and: construction effort on the.test device. Additional theoretical work must be done, and the results applied to the design and construction work, which is just beginning. Procurement of many critical materials and parts must be accomplished, and new technical problems must be solved, including for the first time the prepnration and handling of large quantities of liquid deuterium and liquid hydrogen, re 22, a major undertaking in itself. In addition to the 1952 test project, consideration continues to be given to ail feasible avenues of approach to a thermonuclear weapon. (One approach which appears promising involves the use of lithium 6, which is discussed above.) work involves fundamental theoretical investigations, of the performance of different systems, ‘This calculations experimental physical measurements, and other leboratory and enginecring work in a variety of fields, such,sas eryogenics, metallurgy, Ape) Cr AID Iina (DR Sickie chemistry, etc, Ce iS Law “Ve the 20-kiloton yicld of the Nagasaki-type atomic bomb.)